Now showing items 1-5 of 5

    • Electrostatic activation of prebiotic chemistry in substellar atmospheres 

      Stark, Craig Ronald; Helling, Christiane; Diver, Declan A; Rimmer, Paul (2014-04) - Journal article
      Charged dust grains in the atmospheres of exoplanets may play a key role in the formation of prebiotic molecules, necessary to the origin of life. Dust grains submerged in an atmospheric plasma become negatively charged ...
    • The first millimeter detection of a non-accreting ultracool dwarf 

      Williams, P. K. G.; Casewell, Sarah L.; Stark, Craig Ronald; Littlefair, S. P.; Helling, Christiane; Berger, E. (2015-12-09) - Journal article
      The well-studied M9 dwarf TVLM 513–46546 is a rapid rotator (Prot ∼ 2 hr) hosting a stable, dipolar magnetic field of ∼3 kG surface strength. Here we report its detection with ALMA at 95 GHz at a mean flux density of 56 ± ...
    • Inhomogeneous cloud coverage through the Coulomb explosion of dust in substellar atmospheres 

      Stark, Craig Ronald; Helling, Christiane; Diver, D. A. (2015-07) - Journal article
      Context. Recent observations of brown dwarf spectroscopic variability in the infrared infer the presence of patchy cloud cover. Aims. This paper proposes a mechanism for producing inhomogeneous cloud coverage due to the ...
    • Ionization in atmospheres of brown dwarfs and extrasolar planets III. Breakdown conditions for mineral clouds 

      Helling, Christiane; Jardine, Moira Mary; Stark, Craig Ronald; Diver, D. (2013-04-20) - Journal article
      Electric discharges were detected directly in the cloudy atmospheres of Earth, Jupiter, and Saturn, are debatable for Venus, and indirectly inferred for Neptune and Uranus in our solar system. Sprites (and other types of ...
    • Reference study to characterize plasma and magnetic properties of ultracool atmospheres 

      Rodriguez-Barrera, Maria Isabel; Helling, Christiane; Stark, Craig Ronald; Rice, Anna (2015-12-21) - Journal article
      Radio and X-ray emission from brown dwarfs (BDs) suggest that an ionized gas and a magnetic field with a sufficient flux density must be present. We perform a reference study for late M-dwarfs (MD), BDs and giant gas planet ...